Senior/Staff Backend Engineer

 

About Ethos

Ethos is on a mission to bridge the human readiness gap by transforming how training is developed, consumed, and aligned with strategic business outcomes. As a well-funded Series A startup ($40M+ raised), we are a trusted partner to over 150 enterprise customers across sectors including the U.S. military, life sciences, manufacturing, supply chain, and professional sports. We are expanding our engineering team to evolve a best-in-class platform that makes learning smarter, faster, and more optimized. 

 

About the Role 

You’ll lead the modernization of our legacy backend into a Go-based, service-oriented architecture that scales from single-tenant installs to internet-scale multi-tenant SaaS. As a Senior engineer, you’ll own end-to-end feature delivery, shape architecture, and work closely with Product and Data. As a Staff engineer, you’ll additionally guide pods, drive technical strategy, and influence foundational capabilities—especially distributed systems, data flows, and AI integrations. 

If you love hard systems problems, have deep Go expertise, and can lift a legacy platform into a modern, AI-ready stack, this role is for you. 

What You’ll Do

• Design & Build Services: Implement well-factored Go services and APIs; own features from requirements through deployment and post-release iteration.
• Modernize the Platform: Decompose legacy components; define clear domain boundaries and contracts; ship migrations with backward compatibility.
• Performance & Reliability: Improve latency/throughput; apply caching, connection pooling, rate limiting, backpressure, idempotency, and resilient retries.
• Data & Messaging: Model schemas and data contracts; build event-driven workflows with queues/streams (e.g., Kafka/RabbitMQ).
• Quality by Default: Raise the bar on testing (unit/integration/e2e), code quality, observability hooks, and safe rollout/rollback patterns.
• Technical Leadership: Lead design reviews, write RFCs/ADRs, mentor teammates, and drive consistent standards.
• (Staff) Strategy & Influence: Define service boundaries, shared libraries, and platform conventions; steer cross-team initiatives and the long-term technical roadmap.

Measures of Success (First 6–12 Months)

• Latency & Errors: Reduce p95/p99 API latency by ≥30%; keep error rate on key endpoints ≤0.1%.
• Delivery: Increase feature throughput and deployment frequency without raising change failure rate.
• Quality: Reach and sustain ≥80% meaningful test coverage on core services; reduce flaky tests.
• Decomposition: Retire targeted legacy endpoints/services and replace them with well-bounded Go services behind stable contracts.
• AI Enablement: Ship at least one production feature using retrieval/LLM or model-driven workflows with clear guardrails and metrics. 

30/60/90 Day Plan

First 30 Days — Map & Baseline

• Inventory legacy components, data flows, and integrations; document pain points and quick wins.
• Establish baseline KPIs (latency, error rate, throughput, deploy cadence).
• Land first improvements (bug fixes, hotspots, small perf wins). 

60 Days — Design & Deliver

• Propose target service boundaries and a pragmatic migration plan; align via RFCs/ADRs.
• Implement the first Go service (or major refactor) with contracts, tests, and dashboards/alerts.
• Introduce resilience patterns (timeouts, circuit breakers, idempotency, DLQs) and data-migration scaffolding. 

90 Days — Scale & Standardize

•  Move priority traffic to new paths; deprecate legacy code safely behind flags.
• Drive sustained performance gains (caching, query optimization, parallelism) and lower cost per request.
• (Staff) Contribute to the 12–18 month technical roadmap (service map, shared libs, data/event strategy, AI integration patterns). 

Basic Qualifications 

• 5+ years building enterprise-scale backend systems; 3+ years in Go for production SaaS.
• Deep Go expertise (concurrency, memory, profiling, error handling) and strong API design (REST/gRPC).
• Hands-on with messaging/streaming (Kafka or RabbitMQ) and event-driven architectures.
• Solid understanding of relational databases and caching (schemas, indexing, transactions, Redis).
• Product-mindful: translate user stories into technical plans and make pragmatic trade-offs.
• Demonstrated excellence in system design, testing strategy, CI/CD, and code quality.
• Clear communication and collaboration across engineering and product.
• Comfortable in a startup environment—ownership, autonomy, and bias for delivery. 

Preferred Qualifications

• Passing familiarity with PHP (to navigate and migrate legacy components).
• Working knowledge of React and related frontend frameworks to ease integration with frontend teams.
• Production experience integrating AI (LLMs, RAG, agents) with attention to cost, latency, and safety/guardrails.
• Deployed Go services with Docker and Kubernetes (Helm; Argo CD/Flux); blue-green/canary rollouts.
• Strong observability chops (OpenTelemetry, Prometheus/Grafana, Datadog) and performance profiling at scale.
• (Staff) Evidence of org-level impact: setting standards, leading cross-team initiatives, and mentoring. 

Compensation & Benefits

• Competitive base salary (Senior: $150k-170k; Staff: $170k-195k) based on location and experience with significant equity upside
• Subsidized health insurance, 401(k), life insurance, and cell phone stipend.
• Remote-first culture with up to 10% travel for offsites.
• Work eligibility: Applicants must be authorized to work in the U.S.

One Final Note

We’re committed to building a diverse, inclusive, and authentic workplace. If you’re excited about this role but your experience doesn’t perfectly align with every qualification, please apply—you may be just the right candidate.

EEO & accommodations: Ethos is an Equal Opportunity Employer. We welcome applicants of all backgrounds and provide reasonable accommodations throughout the hiring process.