Senior SAAS Engineer and Platform Architect

**Job description:** **Senior SAAS Backend Engineer and Platform Architect \- Contract** **Note to Candidates.** * This is a full\-time and fully remote CONTRACT role and can lead to **conversion to FTE** * **Apply ONLY if you live in the US and can work Eastern hours** * **No ΝΟ ΝΟ** Third parties please, **employers please do not call** * We will only **consider GC and USC only**, we cannot work with sponsorships. * Candidates must be able to prove US work authorization during interview **About the Role** We are seeking a highly experienced Senior **SAAS** Backend Engineer and Platform Architect with experience in real\-world scaling and performance challenges, to join an established SaaS company. This is a hands\-on role for someone who thrives on diagnosing broken systems, fixing hard problems, and leaving a platform measurably better than they found it. You will own backend performance, API integrity, and data architecture end to end. If you have spent your career building and fixing high\-traffic multi\-tenant SaaS platforms and you are the person your team calls when nothing else works \- this role is for you. **What We Are Looking For** * **12\+ years** of professional backend engineering experience building and operating production SaaS systems * **Very strong** multi\-tenant SaaS architecture experience \- tenant isolation, data segregation, noisy neighbor mitigation, and per\-tenant scaling * **Expert\-level MongoDB** \- schema design, indexing, query optimization, aggregation pipelines, and performance troubleshooting on live systems * **Strong API design experience** \- REST and GraphQL, versioning strategies, N\+1 problem resolution, and contract management * **Strong Node.js proficiency** \- event loop management, memory leak detection, async patterns, and worker thread usage * **Deep knowledge of data modeling, normalization, and ensuring data integrity** across distributed systems * Experience shipping and operating highly reliable systems in cloud environments (AWS, GCP, or Azure) * Ability to operate independently and make sound architectural decisions without heavy oversight * Strong communicator who asks the right questions early and reduces downstream risk **Nice to Have** * Experience with job queue systems * **Familiarity with observability tooling**\- APM, distributed tracing, synthetic monitoring * Experience with canary deployments, chaos testing, or fault injection * Background in establishing SLOs and SLA monitoring **What You Will Do** * **Diagnose and resolve performance bottlenecks across the full backend stack**: APIs, database layer, and application services * Architect and **optimize a multi\-tenant SaaS platform** for stability, scalability, and release readiness * Design, harden, and version **REST and GraphQL APIs** with a focus on reliability and backward compatibility * **Optimize MongoDB performance including schema design, indexing strategies, query optimization, and transaction management** *