Senior Software Engineer

As a Senior Software Engineer at Posh, you’ll play a pivotal role in shaping the intelligence layer that powers the future of banking experiences. You’ll be building the backbone of our AI-driven ecosystem — the systems that make our conversational assistants smarter, faster, and more capable of understanding and solving real customer problems for financial institutions.

You’ll take ownership of critical backend systems, from optimizing RAG (Retrieval-Augmented Generation) pipelines and integrating LLM inference workloads, to designing scalable services that orchestrate our proprietary NLP and ML utilities. Your architectural decisions will directly influence how our AI assistants think, reason, and respond — powering millions of conversations every month.

This isn’t a role for passive implementers. You’ll collaborate closely with product and ML teams to innovate across our platform, lead technical initiatives from design to deployment, and guide other engineers toward technical excellence. You’ll work in an innovative environment where curiosity, craftsmanship, and a bias for action are celebrated — and where your work will have an immediate, measurable impact on how financial institutions serve their customers.

• Optimize critical backend systems, including RAG pipelines (ingestion and inference) and orchestration of ML utility services.

• Design and implement new features and quality improvements across our cross-product RAG API — including tools, disambiguation, and dynamic reasoning model use.

• Improve application reliability and scalability while solving complex technical challenges.

• Add monitoring, alerting, and anomaly detection to enhance operational responsiveness.

• Write clean, maintainable, and testable code that’s easy to understand and ready for change.

• Maintain, extend, and refactor existing systems and legacy codebases.

• Collaborate with engineering peers, product managers, and designers to deliver world-class solutions.

• Define and promote software engineering best practices, including testing, code reviews, and architectural standards.

• Experienced Engineer: 5+ years of full-stack experience with a focus on backend systems; proficient in TypeScript and React.

• Technical Leader: 2+ years leading projects and mentoring engineers.

• AI Champion: Hands-on experience integrating LLM inference into production; familiar with LLM latency optimization, evaluation design, and prompt tuning for UX outcomes.

• Architectural Expertise: Skilled in designing scalable, fault-tolerant systems and anticipating implementation challenges.

• Database Proficient: Strong experience with PostgreSQL or MySQL, with a focus on efficient queries and performance tuning.

• Collaborative & Adaptable: Excellent communication skills; thrives in ambiguity and embraces change.

• Quality-Driven: Writes code that is maintainable, robust, and secure.

• Continuous Learner: Stays ahead of emerging technologies and trends, especially in AI and software scalability.

• Languages & Frameworks: TypeScript, Python, Node.js, React.js

• APIs: GraphQL, REST, WebSockets

• Databases: PostgreSQL, BigQuery, ElasticSearch

• Infrastructure: Docker, Kubernetes, Google Cloud, Event-driven Pub/Sub

• Version Control & CI/CD: GitLab, CI

• AI & ML: Proprietary NLP/ML services, RAG ingestion pipelines, OpenAI & Google LLMs

• Collaboration Tools: JIRA, Confluence, Slack, Google Workspace

• Other Tools: Twilio, Frontier LLM providers, BYO IDE (paid by Posh; most use Cursor)

Posh is a hybrid workforce, with employees located across the United States & Canada, and our home base located in Boston, MA. We’re a small and mighty team that prides ourselves in a tasteful balance between voracity and disciplined craftsmanship. We value those who embrace ambiguity - who leverage their curiosity and passion to push the boundaries of their knowledge in order to build exceptional products. Our tech stack is a combination of TypeScript (node.js and React) and Python, hosted in a scalable and distributed multi-cluster Kubernetes environment. We don’t expect everyone to have prior experience in all of our tools, but we expect fundamental competency and intellectual curiosity.

Our products are award-winning, backed by a dream team of top-tier fintech investors with over $45 million in funding to date.

Our company does not discriminate in employment on the basis of race, color, religion, sex (including pregnancy and gender identity), national origin, political affiliation, sexual orientation, marital status, disability, genetic information, age, membership in an employee organization, retaliation, parental status, military service, or other non-merit factor.

Applicants must be authorized to work for any employer in the U.S. We are unable to sponsor or take over sponsorship of an employment Visa at this time.