Top Senior Software Engineer Jobs in Portland, ME

Design, build, test, and maintain low-latency, high-throughput trading services on an Aeron-based platform. Expand trading protocol features, migrate workflows to the new stack, optimize performance and scalability, support production reliability, and collaborate with cross-functional teams while using AI-assisted development tools.

Build and maintain Mozilla’s Internal Developer Infrastructure Platform, including CI/CD, observability, Kubernetes optimization, environment bootstrapping, and cloud cost optimization. Support development teams, guide technical decisions, create platform features and agentic workflows, improve developer productivity, and promote maintainable engineering practices. The role also requires cross-functional collaboration, technical leadership, proposal writing, and resolving ambiguous infrastructure challenges.

Lead quality assurance for storage and filesystem features, designing test strategies, executing system, stress, regression, and cross-functional testing, and developing automation. Collaborate with developers, tools teams, and customer support to improve testability, reproduce issues, and debug defects. The role requires expertise in NFS, SMB, NAS filesystems, Linux, Windows, VMware, shell scripting, Python, packet capture, test infrastructure, and release management.

Designs and implements scalable software architecture and web-based systems using Java EE and related technologies. Responsibilities include developing front-end and backend functionality, evaluating tools and designs, troubleshooting, conducting root-cause analysis, collaborating with QA and project teams, participating in code reviews, documenting solutions, mentoring engineers, and serving as a technical lead across multiple projects.

The Senior Back-End Software Engineer designs, develops, and maintains scalable backend systems while taking ownership of the software development lifecycle.

Build and operate scalable Kubernetes (EKS) infrastructure, develop Terraform infrastructure-as-code, maintain internal developer platform and tooling, support automation, security, and performance, and participate in 24x7 on-call rotations and incident escalation.

The role involves designing, building, and optimizing a data platform, collaborating with cross-functional teams, and ensuring data quality and security.

Develop and maintain high-volume, mission-critical enterprise web applications using C#/.NET, ASP.NET MVC, AngularJS, and SQL Server. Responsibilities include full lifecycle development, architecture and design participation, troubleshooting, performance and scalability improvements, AI-assisted workflow development, Agile collaboration, technical mentoring, and supporting multi-tier systems.

Lead end-to-end design, development, deployment, testing, and production support of enterprise web applications. Build scalable client/server architectures, ensure security and data governance, mentor team members, collaborate with product and business stakeholders, and own timely delivery and quality of solutions. Analyze data patterns and support reporting and selection workflows.

Develops and supports software solutions for federal IPv4-to-IPv6 network and application transitions. Responsibilities include software lifecycle development, systems analysis, technical documentation, IPv6 modifications, cloud recommendations, automated networking deployment workflows, and technical leadership across complex assignments. The role is fully remote and may involve supervising others.

Build and maintain full-stack systems for a global monitoring application supporting federal partners and satellite data access. Responsibilities include designing scalable backend services and frontend applications, improving architecture and infrastructure, integrating complex customer requirements, and owning mission-system quality and availability. The role requires collaboration across teams throughout the engineering lifecycle and experience with cloud infrastructure, observability, geospatial data, and complex integrations.

Design and build platforms for new products, develop generative AI features, ensure system reliability, and foster a collaborative culture in a startup environment.

Develops and sustains modernized software applications for NAVSUP BSC, including coding, integration testing, documentation, debugging, cybersecurity, CI/CD automation, artifact management, and production support. The role requires Java, JavaScript, SQL, Oracle, .NET, C#, DevOps, cloud-native architecture, infrastructure as code, and secure software development experience. Responsibilities include designing common services, maintaining existing systems, supporting Agile teams, conducting quality audits, and collaborating with engineering, security, operations, and government stakeholders.

Lead design and implementation of Doowiis frontend, backend, and data systems. Define architecture, build scalable ingestion and analytics pipelines, optimize storage and query performance, ship AI-driven features (LLM/text-to-SQL, embeddings), improve observability and deployment, and mentor engineers while partnering with product and ML teams.

Develop and maintain scalable full-stack web applications using TypeScript, Java, Node.js, HTML, CSS, and MS SQL in a microservice environment. Build AI-powered applications with LLMs, GenAI agents, RAG pipelines, semantic search, vector databases, and LLMOps practices. Collaborate across teams, optimize performance, troubleshoot issues, participate in code reviews, and create responsive user interfaces.

As a Staff Software Engineer, you will define technical strategy for Drive-Thru solutions, standardize Android practices, and ensure seamless integration between mobile clients and backend services while mentoring peers.

As a Senior Software Engineer, you will design best practices for AI Agents, develop standards, collaborate on product opportunities, and stay updated on emerging Agent techniques.

Drive the Continuous Integration team, ensuring build systems' reliability and scalability, and mentor CI engineers while improving developer productivity through automation and tooling.

The Senior Software Engineer at Order.co designs complex features end-to-end, mentors junior engineers, and participates in design reviews while ensuring quality and reliability of systems.

Lead technical design, build, and operate scalable, secure healthcare integration systems. Drive architecture, event-driven distributed systems, APIs, observability, IaC, CI/CD, incident response, cross-functional delivery, and mentor engineering teams.

Build and launch user-facing, backend-leaning full-stack products for a clinical AI platform. Design reusable accessible frontend components, develop backend features, collaborate with product managers and subject matter experts, protect patient privacy through secure coding, improve engineering practices, and support applications in production.

Design, develop, and maintain Android point-of-sale software for high-availability, real-time restaurant systems focused on payments. Collaborate with product, design, and backend teams to deliver features, ensure quality through testing and code reviews, and address complex technical challenges. Provide technical leadership and mentorship while contributing to subsystem design focused on scalability, security, and performance.

Develop and maintain spacecraft flight software across the full lifecycle: requirements, design, implementation, testing, integration with HIL and flight hardware. Build tools and simulations, perform subsystem and platform-level tests, support anomaly resolution, systems modeling, and proposal efforts while collaborating with manufacturing and customers.

Design, build, test, and maintain React Native features for Hertz consumer mobile apps on iOS and Android. Collaborate with cross-functional teams, integrate APIs and third‑party services, optimize performance, resolve production issues, contribute to CI/CD and testing, and improve mobile UX and accessibility.

Senior backend engineer responsible for setting technical direction, designing scalable distributed systems, building customer-facing web applications, mentoring engineers, and applying machine learning to large-scale healthcare data. The role requires Java, Scala, or Rust expertise, cloud systems experience, technical design leadership, cross-functional collaboration, and adoption of agentic engineering practices.