Mid-Senior Backend PHP Developer

Join our dynamic team at Artech Information Systems LLC as a Backend PHP Developer. In this role, you will contribute to the design and implementation of robust backend systems using PHP. You will work alongside a talented group of developers, collaborating on exciting projects that drive innovation and efficiency.

Join our dynamic team at usm2 as a Senior Full Stack Developer, where you will play a pivotal role in developing robust applications that enhance user experience and functionality. Your expertise in both frontend and backend technologies will be crucial to our innovative projects. Collaborate with cross-functional teams, contribute to design discussions, and implement best coding practices to deliver high-quality solutions.

At WHOOP, we are dedicated to transforming human performance and enhancing healthspan. Our mission is to empower members to achieve peak performance through a profound understanding of their bodies and daily lives. With our cutting-edge wearable technology, we monitor essential physiological metrics to provide tailored insights that boost fitness, health, and recovery.The Growth Team at WHOOP is a dynamic, results-oriented group committed to driving user acquisition, activation, and retention. Our data-centric approach enables us to continuously assess the effectiveness of our features and iterate based on those insights.As a Senior Backend Software Engineer, you will be instrumental in constructing backend services that significantly influence our business metrics and foster member growth. Collaborating cross-functionally, you will deliver impactful features and contribute to architectural decisions, ensuring WHOOP's scalability to millions of members.

About WHOOP WHOOP helps people understand their bodies and habits so they can perform at their best and improve their healthspan. The team builds tools and insights that support members in reaching their goals every day. Role Overview The Senior Backend Software Engineer - Health Records will design and build the systems that connect external healthcare data with the WHOOP platform. This work ensures health data is integrated securely and can scale as needs grow. The role focuses on transforming complex health records into insights that members can use, strengthening WHOOP’s ability to deliver personalized health experiences and long-term value.

Join Klaviyo as a Senior Solutions Engineer focused on Mid-Enterprise clients. In this pivotal role, you will leverage your technical expertise and consultative approach to drive innovative solutions that empower businesses to achieve their marketing goals. Collaborate closely with sales teams to understand client needs, design tailored solutions, and deliver exceptional results.

At WHOOP, we are dedicated to empowering individuals to enhance their performance and extend their healthspan. As a Senior Software Engineer on our Business Systems team, you will be instrumental in designing and implementing robust backend systems that drive WHOOP’s internal operations. Your efforts will facilitate scalability and operational efficiency across various departments, including Finance, Operations, and Member Services. By architecting and maintaining critical services and integrations, you will play a crucial role in ensuring that our systems are reliable, secure, and high-performing, ultimately helping WHOOP deliver exceptional value to our members and support our global growth ambitions.

Location: Waltham, MA (Hybrid – 3 days in office) Next Insurance is looking for a Backend Engineer to join the Development Experience Team. This position centers on platform engineering, with a focus on supporting U.S.-based teams and connecting their needs with global infrastructure projects. Role overview This role takes a lead position in shaping the strategy for an Agentic (AI-based) Software Development Life Cycle. The goal is to move beyond simple automation and build a future where AI agents support every stage of the SDLC, from design to deployment. Deep backend coding skills are essential, as the work will directly influence how U.S. engineering teams adopt and benefit from these AI-driven tools. Key responsibilities Act as a technical anchor for local platform engineering initiatives. Bridge U.S. engineering needs with global infrastructure efforts. Architect and maintain Next Insurance’s cloud-only infrastructure, treating the platform as a product. Identify platform challenges and lead projects that improve developer experience and drive business value. What you will work on Develop and refine tools and processes to enhance the software development life cycle using AI agents. Work across a wide range of cloud and application infrastructure technologies. Collaborate with engineering teams to understand pain points and deliver solutions that make daily work more efficient. Since 2016, Next Insurance has provided fast, customized, and affordable coverage to small businesses across the U.S. The company continues to grow with support from leaders in both insurance and technology, aiming to transform the customer experience and empower entrepreneurs everywhere.

At WHOOP, we are dedicated to revolutionizing human performance and extending healthspan. By leveraging cutting-edge wearable technology, WHOOP empowers our members to achieve peak performance through an in-depth understanding of their physiological metrics and daily habits. Our devices monitor vital metrics to deliver personalized insights that optimize fitness, health, and recovery. As a Senior Software Engineer (Backend) concentrating on Core & Ecosystem, you will be instrumental in constructing and enhancing the robust systems that underpin the WHOOP member experience related to sleep, strain, and recovery. Your contributions will also facilitate the WHOOP connected experience for both new and existing partnerships, as well as external developer applications and supporting platforms. This team is charged with creating the infrastructure and shared services that drive data pipelines, algorithms, and scalability across our product. You will work closely with product management, design, data science, and your fellow engineers to architect and implement reliable, impactful backend systems that support features for our members. You will lead the technical planning for complex projects, mentor junior engineers, and elevate the standard of engineering excellence within the backend team.

Join our innovative team at Lever as a Backend Engineer, where you will play a pivotal role in crafting cutting-edge software solutions that transform the hiring landscape.At Lever, we are dedicated to revolutionizing the way companies recruit top talent. Our software is trusted by industry leaders like Netflix, Yelp, Cirque du Soleil, Shopify, and Spotify. As we continue to grow, we seek talented individuals who are passionate about redefining talent acquisition.We are proud to be recognized as the #1 workplace in San Francisco and a top employer in the United States. Our team, known as “Leveroos,” is our greatest asset, and we are committed to fostering a people-first culture that celebrates collaboration and innovation.

We are on the lookout for a highly skilled Senior Backend Software Engineer to become an integral part of our dynamic team. In this role, you will collaborate in the design, implementation, and deployment of our core data pipeline and processing platform for our innovative AI-native cloud environment. Your expertise will be pivotal in creating robust, scalable, and sophisticated solutions to tackle intricate cybersecurity challenges. You will take charge of selecting and implementing the essential technologies and architectures needed for success.Key Responsibilities:- Architect, implement, and maintain the foundational data pipelines and processing platform for our AI-native cloud services.- Develop high-quality, scalable, and elegant solutions for complex cybersecurity scenarios.- Evaluate and integrate appropriate technologies and architectures.- Guarantee the scalability, reliability, and performance of our cloud-based offerings.Qualifications:- A minimum of 7 years of experience in backend development.- Proven hands-on experience with cloud architecture and deployment.- Familiarity with a diverse array of cloud technologies and architectural frameworks.- Exceptional software development skills, coupled with a proactive, fast-paced approach to shipping solutions.- Bachelor's degree or equivalent in a relevant discipline.- Strong analytical thinking and communication abilities.About Seven AI:At Seven AI, we welcome professionals at all levels who are passionate about making a significant impact and thriving in a fast-paced, growth-oriented environment. With the rapid advancement of AI technology, this is an exciting time to join us, where your skills can influence the future of cybersecurity. You will engage with cutting-edge technology and spearhead innovative solutions while working alongside industry experts committed to safeguarding against emerging AI-driven threats. Our culture emphasizes respect, collaboration, and a shared dedication to delivering exceptional value to our clients. If you are enthusiastic about building remarkable solutions and desire to be in an environment where your contributions are valued, we would love to hear from you.

Join our dynamic team at Sonsoft Inc. as an Archer with Open Pages. In this pivotal role, you will leverage your expertise to enhance our applications, ensuring seamless integration and optimal performance. We are looking for a proactive professional who is passionate about problem-solving and is keen to make a significant impact in our organization.

Join us in transforming how the Department of Defense approaches multi-billion-dollar force-design decisions. As a Senior Backend Platform Engineer, you will integrate physics-driven simulations, interactive computing, and validated AI code generation to develop cutting-edge wargaming platforms. If the prospect of creating ultra-low-latency APIs, managing high-volume geospatial data, and leading with clean, production-ready Python excites you, we want to hear from you!Your ResponsibilitiesOwn the service layer: Design, build, and scale FastAPI microservices and ultra-fast ZeroMQ messaging pipelines in Kubernetes and bare-metal clusters.Wrangle data at speed & scale: Shape and query multi-TB Postgres/PostGIS datasets, orchestrate Redis for sub-millisecond state, and ensure stability under bursty loads.Glue the stack together: Expose crisp, well-versioned REST & WebSocket endpoints for the frontend team and simulation kernel.Ship continuously: Automate CI/CD, observability, and security hardening to meet DoD standards; deploy to production with confidence.Lead by example: Drive code reviews, mentor team members, and set the standard for test coverage and documentation.Why Choose Code Metal?Mission with Impact: Your work will contribute to the digital infrastructure of modern battlefields, influencing multi-billion-dollar defense acquisitions.Velocity: Work in tight-knit teams with weekly releases and no bureaucratic delays.Ownership: Every engineer is empowered to ship significant code without being a passenger.

At Toast, we are passionate about creating a revolutionary restaurant platform that empowers restaurants to reclaim their passion and focus on what they do best: nurturing their beloved businesses. We pride ourselves on being an unconventional tech company that thrives on innovation. Challenging the status quo is embedded in our culture. Building a transformative product necessitates forward-thinking, which is why we deeply value diverse backgrounds and experiences. Our mission is to enable restaurants of all sizes to assemble exceptional teams, boost revenue, streamline operations, and offer unforgettable guest experiences. By combining our extensive knowledge of the restaurant industry with robust cloud-based software and top-tier hardware, we deliver an intuitive all-in-one solution. Join us in our quest to uplift the restaurant community, delight guests, and help them flourish. Our Fintech division at Toast plays a pivotal role in our infrastructure by managing payments for restaurants and ensuring timely transactions. Payment processing is not only a vital revenue stream for Toast but also essential for our customers, as we handle millions of dollars in transactions daily. We are on the lookout for a Senior Software Engineer to enhance our Payments team and develop our unified payment processing platform. This solution provides a seamless, integrated service for accepting payments across various channels and supports a configurable enterprise approach. It is engineered to enable a build-once, available-to-all strategy for both existing and emerging payment methods. The right candidate will play a crucial role in creating services that provide essential support and functionality within this payment processing framework.

About HTS MediaHTS Media, a dynamic division of Hopper, is revolutionizing the way travel brands engage with consumers. Our platform seamlessly connects travel brands, destinations, and suppliers with travelers, leveraging our app and extensive B2B partnerships with industry giants like Capital One Travel and TripAdvisor. Our goal is to establish the leading retail media network in the travel sector, driving significant profitability for Hopper and our partners, much like Instacart, Uber, and Amazon have achieved in their respective industries.Though we are in the early phases of our development, HTS Media has already emerged as one of Hopper’s most rapidly expanding and profitable segments. The engineering team is crucial in enhancing our platform, ensuring that our ad technologies provide tangible benefits for advertisers while delivering a seamless user experience for travelers.About the RoleAs a Senior Backend Engineer on the HTS Media team, you will be instrumental in developing the core engine that drives our advertising platform. Your responsibilities will include designing, constructing, and scaling high-throughput, low-latency services that manage ad requests, conduct auctions, and deliver millions of targeted offers to travelers in real-time. This pivotal position will have a direct influence on platform performance, advertiser satisfaction, and Hopper’s overall financial success.You will confront the intricate challenges within the ad tech arena, optimizing our real-time bidding (RTB) logic and ensuring responses occur within milliseconds, even under heavy loads. As a technical leader, you will mentor other engineers, guide architectural choices, and uphold high standards of scalable, high-quality code. If you have a passion for building distributed systems capable of operating at an extensive scale, this is the perfect opportunity for you.

At WHOOP, we are dedicated to enhancing human performance and extending healthspans. Our innovative enterprise platform empowers organizations in athletics, business, healthcare, and public service to gain deeper insights into the health and performance of their teams.As WHOOP Enterprise embarks on an exciting new phase of growth and reinvestment, we are seeking a passionate Senior Software Engineer to play a vital role in transforming our Enterprise platform. You will be responsible for developing core systems, influencing technical direction, and establishing a robust foundation for a scalable enterprise product.This position offers significant ownership and autonomy, allowing you to thrive in a product-ambiguous environment. You will help define excellence in our offerings and work closely with design, stakeholders, and leadership as we propel the platform forward.

Foundation LLM Technologies, a venture-backed startup founded at MIT, is building an AI Copilot for design and manufacturing. The team blends artificial intelligence, physics simulation, and computer graphics to streamline engineering work and lower costs throughout the design and manufacturing lifecycle. Role overview This Senior CAD Backend Engineer position focuses on backend integrations and automation for the company's AI engineering platform. The role emphasizes connecting CAD systems, particularly CATIA, to cloud-native services, automating mechanical design workflows, and developing backend features in Python. Deep expertise with CATIA is essential. Key responsibilities Develop backend integrations linking CATIA with cloud services Automate mechanical design processes within the platform Create and maintain backend features using Python Optimize workflows to enhance engineering productivity Requirements Extensive experience with CATIA and CAD APIs Strong Python programming skills Background in mechanical design automation and backend development Location Boston, MA

At WHOOP, we are dedicated to revolutionizing human performance and extending healthspan. Our mission is to empower individuals to reach their optimal potential by providing comprehensive insights into their physiological well-being through our cutting-edge wearable technology. By continuously monitoring vital metrics, we deliver personalized recommendations that enhance fitness, health, and recovery.The Growth Team at WHOOP embodies a dynamic, fast-paced, and experimentation-focused environment. Our primary objective is to drive user acquisition, activation, and retention through a data-driven approach. We rigorously evaluate the performance of our features and iterate based on quantifiable results.As a Software Engineer II on the Growth Team, you will play a pivotal role in developing features that significantly influence our business metrics and member growth. Your collaboration with cross-functional teams will be essential in designing, measuring, and refining high-impact mobile experiences that resonate with our users.

At WHOOP, our mission is to enhance human performance and extend healthspan. We empower our members to optimize their performance and longevity through profound insights into their bodies and daily routines. A critical aspect of our mission is safeguarding our members' data while ensuring our systems scale securely and reliably. We are seeking a talented Software Engineer II specializing in backend development to build and refine the systems that fuel our platform. This pivotal role will play a direct part in delivering scalable and secure services that support millions of members globally. While backend development expertise is essential, familiarity with cybersecurity principles (such as data privacy, authentication, and authorization) or cloud infrastructure concepts (including AWS, Infrastructure as Code, and Kubernetes) will be highly regarded. This position offers a unique opportunity to align with either our Product Security team, focused on security compliance and data privacy, or our Application Infrastructure team, which emphasizes scalability, reliability, and developer support. In either capacity, you will help shape core platform practices and contribute to WHOOP's growth trajectory.

At WHOOP, we are driven by a commitment to enhancing human performance and extending healthspan. Our platform empowers a wide range of members, from Olympians and professional athletes to fitness enthusiasts, enabling them to achieve their peak potential by gaining profound insights into their bodies and daily lives. We are eager to welcome highly skilled and motivated engineers to join our team, propelling our established system to unprecedented heights. Join the AI Platform team at WHOOP where we are tasked with building a robust foundation that facilitates the scalable, responsible, and accessible implementation of Generative AI across our diverse array of products. Our primary focus is on creating reusable infrastructure, services, and tools that empower both product and software teams to explore, integrate, and deploy GenAI-powered features both efficiently and securely. By simplifying the complexities associated with large language models (LLMs) and ensuring the delivery of personalized insights to our members, our platform accelerates innovation while maintaining a consistent, high-quality user experience. As a Senior Software Engineer on the AI Platform team, you will play a pivotal role in designing and scaling the systems that underpin WHOOP’s Generative AI capabilities. You will develop robust, modular services and user-friendly tools that streamline the interaction with GenAI models across the organization. This position merges a platform-oriented mindset with engineering excellence, helping WHOOP unlock the full potential of Generative AI across our core products, coaching services, insights, and beyond.

WHOOP helps people understand their bodies and improve their health. Our platform supports members in reaching their goals by giving them deeper insight into daily performance and well-being. About the Role The Software Engineer II (Backend, Health Records) will focus on building systems that securely handle and process health data. This work supports the integration of external healthcare sources with WHOOP’s platform, making it possible to turn complex records into useful, actionable information. What You’ll Do Develop and maintain backend systems for health data ingestion and processing Ensure solutions are secure and scalable Help connect external healthcare ecosystems to WHOOP’s platform Transform raw health records into insights that support personalized health experiences Contribute to projects that expand WHOOP’s ability to deliver long-term value to members Location This role is based in Boston, MA.