Software Engineer (Integration/API)

About theta.

theta. is an SBA-Certified 8(a) & HUBZone digital integration and management firm based in Baltimore, MD, working to create a world where tech works for everybody. Our mission is to bridge the gap between the intersection of innovation & technology and practical applications that serve the public interest.

We specialize in creating software that enhances efficiency, security, and accessibility in government operations. Our commitment to be of service, be passionate, and be different drives us to deliver projects that make a significant impact.

This position is contingent upon contract award.

Position Overview:

We are seeking a Software Engineer (Integration/API) to build and maintain stable interfaces that connect heterogeneous systems and data sources in complex federal environments. You'll own integration “slices” end-to-end—starting with the interface contract, then implementing adapters/connectors, adding contract and integration tests, and delivering a deployable increment that can be supported in production. 

This role is for someone who understands that integrations fail in the real world; tokens expire, upstream schemas drift, latency spikes, and partial failures happen. You'll build with reliability patterns (clear contracts, backward compatibility, retries/idempotency where appropriate, and meaningful logs/metrics) so interoperability doesn't fragment as deployments scale.

Key Responsibilities:

• Design and implement APIs/integration services and interface contracts.
• Build adapters/connectors to ingest or exchange data across heterogeneous sources.
• Implement versioning and backward compatibility strategies.
• Build contract and integration tests; integrate them into CI/CD.
• Troubleshoot integration failures using logs/metrics and structured debugging.
• Document interface decisions, assumptions, and operational constraints (lightweight ADR/decision log).

Basic Qualifications:

• 5+ years building APIs/integrations in production.
• Strong API design+ versioning discipline; understands backward compatibility.
• Experience integrating with external systems (auth flows, data contracts, edge cases).
• Comfortable writing contract/integration tests and wiring into CI.
• Strong written communication: can write interface specs + acceptance criteria.
• U.S. Citizenship required.
• Must be able to meet any other requirements for government contracts for which they are hired (e.g., must reside in the U.S., Security Clearances).
• Some of our clients may request or require travel from time to time. If this concerns you, we encourage you to apply and discuss it during your initial interview.

Preferred Qualifications:

• Experience supporting federal or defense software programs.
• Event-driven patterns (pub/sub) and message processing concepts.
• Familiarity with telemetry/log-driven debugging.
• Experience working under change-control or governance constraints.

Why Join theta.?:

• Collaborate with a talented and passionate team committed to making a difference.
• Work on impactful projects that directly contribute to the efficiency and effectiveness of our country's operations.
• Enjoy a supportive and inclusive work environment that fosters growth and development.
• Benefit from a competitive compensation package, including comprehensive health benefits, retirement plans, and flexible work arrangements.

If you are a driven and results-oriented integration engineer who enjoys building stable contracts, preventing breaking changes, and making systems reliably talk to each other, even when the real world gets messy, we encourage you to apply and join our team at theta.

Salary Range: $115,000 - $120,000 (DOE and project-specific details)