Senior Software Development Engineer - .Net Technologies

HNR Tech; Mumbai; On-site; INR 8,691,000 - 15,645,000; Full time

Benefits offered by this job

Weekly USD payments

22 PTO/holidays/sick days

Senior team ownership and architecture

Job summary

HNR Tech, a US software company with a 40-year track record, is modernizing its flagship POS platform. You will build the .NET API layer over SQL Server and take ownership of Integration Hub and Communication Hub microservices, shaping architecture with the lead architect.

Expect high performance, low latency, and strong API governance. You’ll work to ship your first production API endpoint within 90 days, delivering end-to-end integrations with suppliers and payment partners, while

Qualifications

• 8+ years of backend engineering with deep design experience.
• Strong .NET/C# or proven proficiency in another compiled backend language plus quick learnability.
• Strong SQL skills and experience with large live production databases.
• Experience with microservices and third‑party API integrations in production.
• Demonstrated performance engineering: memory optimization and low-latency paths.
• Disciplined Git/DevOps practices; clear written and video English communication.
• AI‑fluent and AI‑skeptical approach to development, auditing AI outputs.

Responsibilities

• Build and own the .NET/C# APIs powering the Vue.js frontend and services, business logic, auth, and docs.
• Own and maintain Integration Hub and Communication Hub microservices (SendGrid, Twilio).
• Design integrations with suppliers, payment providers, and partners.
• Optimize for low-latency reads from in-memory caches and heavy server-side caching.
• Shape architecture, coding standards, and API conventions with the lead architect.
• Deliver production endpoints within the first 90 days and own end-to-end integration work.

Skills

Backend design

.NET/C# proficiency

SQL for production databases

Microservices integration

Performance engineering

Git/DevOps practices

English communication

AI-aware development

Tools

Git

CI/CD

SendGrid/Twilio integration

Job description

The Product

A profitable, 40-year-old US software company is modernizing its flagship point-of-sale platform - without the risky rip-and-replace.

Using a strangler-fig approach, a new Vue.js frontend sits over the existing SQL Server database, so customers adopt new functionality gradually instead of surviving a migration.

The original Java POS (2006present) stays in production; both products share one database by design.

You'll build the .NET API layer that makes it work.

What You'll Actually Work On

• Build and own the .NET/C# APIs powering the new Vue.js app - services, business logic, auth, docs.
• Take ownership of two existing microservices: Integration Hub (normalizes supplier/distributor APIs) and Communication Hub (email + SMS via SendGrid and Twilio).
• Design integrations with suppliers, payment providers, and third-party partners.
• Hit a hard low-latency bar on bare-metal Windows servers - heavy server-side caching, most reads from memory.
• Shape architecture, coding standards, and API conventions with the lead architect.

Your First 90 Days

• Ship your first production API endpoint into the Vue.js app, get deep on the Integration Hub's supplier-normalization layer, and own one new supplier or partner integration end to end.

What We Need

• 8+ years of backend engineering with real depth - you've designed services, not just contributed to them.
• Strong .NET/C# - or elite proficiency in another compiled backend language plus proof you learn new stacks fast.
• Strong SQL and comfort working against a large, live production database you didn't design.
• Microservices and third-party API integration at production quality.
• Demonstrated performance engineering: memory optimization, caching, low-latency request paths.
• Disciplined Git/DevOps habits; clear written and video communication in English.
• AI-fluent and AI-skeptical - you move faster with AI, audit everything it produces, and write the hard 10% it can't.

How We Work

• ~20 people, 40+ years in business, profitable, founder-led - zero venture funding, zero committees.
• Credo: build it right the first time.
• The PM prototypes UX with AI and ships to git; engineers productionize.
• AI is expected to multiply a senior engineer's output - and the engineer is expected to catch its mistakes, every time.
• You'll work with the lead architect, a same-time-zone Vue.js teammate, the Product Manager, a Senior Java Engineer joining alongside you, and the founder.
• Tooling: GitHub, dev/staging/production workflow, AI-assisted development with Cursor and Claude.

Hours

• IST with a ~2-hour evening overlap for the US team - roughly 5:308:30 PM IST (810 AM ET).

The Offer

• Long-term, multi-year engagement - not a gig.
• Full-time independent contractor, paid weekly in USD.
• 22 paid PTO/holiday/sick days.
• Small, senior team - real ownership and architectural influence, not ticket-shuffling.