Top Backend Engineer Jobs in Denver & Boulder, CO

Develop and operate backend systems supporting post-transaction processing for Affirm Card. Break down projects, write tested and extensible code, collaborate with product and engineering teams, monitor system health, troubleshoot issues, participate in on-call support, and contribute to code reviews and team development.

Develop and evolve a high-throughput, low-latency US sports betting platform using distributed systems and microservices. Build resilient, scalable services for peak sporting events, collaborate with technical and non-technical stakeholders, contribute to architectural direction, and mentor junior engineers. The role also involves cloud infrastructure, Kubernetes, reliability, concurrency, debugging, and delivery of quality software in an agile environment.

Design, build, and operate backend services for Bestow’s insurance platform using Python, Go, Java, and PostgreSQL. Collaborate on technical decisions, integrations, carrier onboarding, and scalable platform capabilities. Mentor engineers through reviews and pairing, improve production reliability and observability, participate in on-call support, and communicate technical decisions in a remote-first environment. Use agentic AI coding tools daily and help establish effective AI-assisted development practices.

Provides cross-team technical leadership for complex backend initiatives, modular architecture, monolith modernization, API and platform standards, production operations, and AI-assisted engineering adoption. Designs shared patterns for services, data, eventing, security, testing, observability, deployment, and reliability. Partners with Product and Engineering leadership, mentors engineers, participates in incident response, and drives technical strategy without formal authority.

Build, test, ship, and operate production backend features with minimal guidance. Design APIs, background jobs, integrations, data models, migrations, and bounded services while maintaining security, performance, observability, and reliability. Review code, improve automated testing, investigate production issues, address technical debt, participate in operational support, and collaborate asynchronously with product, frontend, infrastructure, and security teams. Use AI coding tools responsibly by validating and correcting generated output.

Owns delivery of backend money movement and card ledger systems, leading engineers through complex problems and ambiguity. Collaborates with product, design, analytics, and engineering stakeholders; defines scalable technical solutions; supports system availability, monitoring, on-call operations, code quality, and engineering standards. The role also includes mentoring and developing team talent while building highly available distributed systems for Affirm’s financial products.

Leads architecture and hands-on development of scalable backend systems and APIs supporting real-time applications. Owns the engineering lifecycle, writes high-performance code, establishes testing and reliability practices, resolves production issues, guides technical roadmaps, collaborates cross-functionally, and mentors engineers. The role requires expertise in object-oriented backend development, distributed cloud systems, automated testing, system monitoring, and technical leadership.

Own and lead the technical direction of a major codebase section while designing, building, testing, documenting, and maintaining secure, scalable API-based decisioning products. Partner with product, engineering, and security teams on agile delivery, troubleshoot production issues, meet SLA requirements, and participate in an on-call rotation.

Build and scale Go backend services for agent quoting, configuration, and application submission. Partner with adjacent teams, resolve partner-specific edge cases, provide architectural leadership, write unit and integration tests, review code, and promote automation, CI/CD, and continuous improvement. The role expects daily use of AI coding tools and ownership of services across distributed systems and microservices environments.

Design, build, and operate backend Go services and smart contracts that mint, burn, bridge, and reconcile wrapped assets across multiple chains. Own end-to-end delivery from smart contract deployment through API design, SLOs, and production rollout. Drive asset migration pipeline improvements, run on-call operations, build observability and runbooks, and mentor junior engineers.

Design and implement secure, scalable backend services for voice agents, integrate AI models and telephony, improve inference, debug concurrent systems, and collaborate with Product to deliver features end-to-end.

Design, build, test, and maintain backend services and APIs powering the insurance platform. Integrate payments, documents, and data providers, improve system stability, performance, and scalability, mentor team members, and participate in architectural decisions and agile ceremonies.

As a Senior Backend Engineer at DuckDuckGo, you'll lead backend projects, mentor engineers, and develop AI-enhanced features for the company's privacy-centric product line.

Design and implement secure, scalable backend services for speech inference and audio processing. Optimize networking, transcoding, latency, memory, and distributed compute orchestration. Measure and improve system performance, debug complex networking/scheduling/HPC issues, customize services for customers, and partner with Product to deliver features end-to-end.

The Staff Software Engineer will lead technical strategy, ensure system availability, and develop backend systems at scale, collaborating across teams to drive capacity modeling and operational quality.

Design and implement scalable backend services for payment and transaction workflows using Java. Own end-to-end features from data model and APIs to Angular frontends, improve reliability and performance, refactor legacy systems, troubleshoot production issues, and collaborate with product and design. Leverage AI-assisted development tools responsibly and share best practices across the team.

Design and implement Kotlin backend services and end-to-end systems for Toast POS device management. Lead technical designs, estimations, performance optimization, cross-team collaboration, and software quality practices including modern testing and observability. Mentor peers and drive product roadmap alignment with product, hardware, and QA stakeholders.

Lead and deliver quarterly goals for a backend team; guide engineers through ambiguous problems; collaborate with product, design, and analytics; identify and resolve project and technical issues; ensure operational availability and on-call readiness; set code and design quality standards; and mentor and develop team members.

Design, build, and operate backend systems for prediction markets, including order management, trade matching, settlement, and market resolution. Architect distributed, low-latency systems with strict financial correctness, lead multi-quarter technical projects, mentor engineers, and collaborate with Product, Compliance, and Risk to meet regulatory requirements.

Develop a platform for liquidity and loan collateralization. Responsibilities include building and integrating data pipelines, creating user experiences, and collaborating with teams for system design.

Lead technical strategy and delivery for backend marketplace/search systems. Collaborate with PM, design, and analytics; own operational reliability, monitoring, on-call, testing, and runbooks; set code/design standards; drive major feature delivery and deprecations; mentor and develop engineering talent.

Design, implement, and optimize high-performance backend systems in Rust for an xOT security platform. Participate across the development lifecycle—debugging, testing, and performance tuning—while integrating relational and NoSQL data stores, microservices, third-party devices, and AI tools. Provide technical leadership, code review feedback, and promote secure, reliable, observable distributed systems.

Design, build, and maintain backend services powering Clerkie's platform. Improve reliability, performance, scalability, observability, and support feature development. Participate in technical design, cross-functional collaboration, documentation, and own projects end-to-end in a fast-moving startup environment.

Lead backend and full-stack work on the Payments team, building multi-gateway integrations (Stripe, PayPal), payment APIs, and customer payment UIs. Ensure secure, compliant (PCI-DSS) payment flows, reliability, observability, and scalability across AWS/Kubernetes microservices. Partner cross-functionally to design architecture, implement settlement/reconciliation, and maintain high availability.

Design, implement, and evolve complex backend features and architecture. Improve reliability, performance, and security at scale. Mentor engineers, participate in incident response, set backend standards, and integrate agentic AI into production workflows.