Job Title: Senior Backend Engineer

Company Name: Efficient Markets

Job Url: https://efficientmarkets.bamboohr.com/careers/31?source=linkedin_premium

Job Description: Senior Backend Engineer (C#/.NET, Azure)
Innovation and Engineering - San Antonio, Texas (Remote)
Role Summary

Efficient Markets is hiring a Senior Backend Engineer to help drive a high-impact migration from a legacy Perl ecosystem to a modern C#/.NET architecture.



This is a backend-first role. We are looking for a senior individual contributor who can own complex, business-logic-heavy backend work, ship production software quickly, and use agentic engineering workflows to increase throughput and quality.



You will partner with existing technical leadership and cross-functional teams, but this role is not a people-management position.



What You’ll Do

Build and evolve core backend services in C#/.NET for business-critical workflows.
Deliver production features across API, data, auth, and admin tooling (Blazor-backed operations).
Own API contract stewardship across Blazor admin, React/Vite web, and React Native/mobile clients.
Keep contracts backward-compatible as systems evolve, using OpenAPI-first change discipline and compatibility checks.
Translate complex domain requirements into reliable, maintainable backend logic.
Contribute to migration strategy and implementation from legacy Perl pathways into .NET services, including coexistence and staged cutovers.
Design and deliver backend behavior that serves both Blazor operational workflows and mobile app consumption patterns.
Improve reliability, observability, security posture, and deployment quality in an Azure-first environment.
Own production operability concerns including instrumentation, health checks, and messaging reliability.
Use AI coding agents effectively for planning, implementation, testing, and iteration through explicit spec-to-implementation loops and measurable quality gates.


Required Qualifications

5+ years building backend systems with C#/.NET in production.
Strong ASP.NET Core API development and SQL-backed domain modeling.
Proven ability to design and maintain APIs consumed by multiple client surfaces without breaking contract stability.
Strong judgment in state-machine or workflow-heavy business domains with strict correctness requirements.
Strong experience with Azure services in production (App Services, Functions, Key Vault, App Insights, Blob Storage, Service Bus, Entra ID).
Strong security/configuration hygiene in production systems (secret handling, identity boundaries, and environment-safe configuration practices).
Proven ability to work in business-logic-heavy systems with evolving requirements.
Strong delivery discipline in Agile workflows (Azure DevOps experience preferred).
Strong written and verbal communication across product, QA, and engineering stakeholders.


Strongly Preferred

Perl experience (maintenance, migration, or interoperability) for near-term migration velocity.
Blazor familiarity in admin/operational interfaces.
Experience with EF Core and Dapper in mixed persistence patterns.
Experience collaborating with React/Vite and React Native teams at backend integration boundaries.
Experience building and enforcing OpenAPI contract governance in CI/CD workflows.
Experience with notification/event delivery and mobile auth/session handoff patterns.
Practical experience with AI-assisted or agentic development workflows using tools such as Codex, Claude Code, Copilot, Cursor, or equivalent.


What Success Looks Like (First 90 Days)

Takes ownership of priority backend migration slices and delivers production increments.
Reduces migration risk while keeping production reliability high through staged coexistence and parity checks.
Demonstrates strong quality and delivery speed in business-logic-heavy areas.
Stabilizes API contracts across admin, web, and mobile consumers while migration work is active.
Establishes repeatable agentic workflows that improve engineering throughput without lowering standards.


Additional Notes

This role is intentionally focused on backend engineering depth, not generic full-stack ownership.
Full-stack familiarity is valuable, but primary professional focus must be C#/.NET and backend architecture.
Perl is strongly preferred, not strictly required.