Senior/Staff Backend Engineer - Search

Mitti; Sydney; On-site; AUD 140,000 - 210,000; Full time

Benefits offered by this job

Equity

Flexible working arrangements

Professional training & development

Hackathons & workshops

On-site gym & amenities

Culinary crew & beverages

Job summary

Mitti by SafetyCulture is scaling AI-powered software for millions of frontline workers. We seek a Senior Software Engineer to own architecture and delivery of large-scale search systems, including multi-tenant deployments, embedding-based retrieval, and AI-assisted features.

You will lead design decisions, mentor peers, and partner with product and design to ship impactful solutions. Equity and flexible work are part of our offer.

Qualifications

• Deep search / information-retrieval expertise including lexical and semantic search.
• Proven track record building search in multi-tenant architectures.
• Strong OpenSearch/Elasticsearch operating experience at scale.

Responsibilities

• Design, build and operate large-scale search across frontend and backend stacks (React, TS, Go, PostgreSQL, OpenSearch) on AWS.
• Own search relevance and retrieval quality; define metrics and optimize ranking and pipelines.
• Lead search architecture: indexing, hybrid retrieval, embeddings, and ranking trade-offs.
• Build AI-native apps connecting retrieval to LLM-powered experiences (RAG).
• Provide technical leadership guiding search architecture, execution, and cross-functional collaboration.
• Own end-to-end delivery of search features with product and design partners.
• Articulate build-vs-buy trade-offs and manage scale, performance, and cost.
• Set engineering standards, mentor peers, and improve team practices.
• Demonstrate Mitti’s values: think customer, open & honest, be bold, act.

Skills

Information retrieval

Search systems

Multi-tenant architecture

RAG (retrieval augmented generation)

Tools

OpenSearch

Elasticsearch

Job description

Why join us?

Mitti by SafetyCulture is a global tech company, just not the kind you’re picturing. Our almost 1,000-person team builds tools that make work better for the three billion frontline workers who keep the world moving. We’ve got big tech scale, without the sign-off layers or corporate theatre. Every permanent team member gets equity, so when we grow, you do too. This next chapter is about scaling smart, powered by AI, a clear vision and real ownership.

Big tech impact, without the big tech ick.

What do Mitti Engineers do?

Our mission and your opportunity is to help solve the challenges faced in an increasingly distributed workforce. In short, to shape Engineering excellence, nurture emerging Engineering talent and build out an inclusive, high-performing interdisciplinary team.

As a Senior Software Engineer, you’ll be empowered to manage complex architectural decisions and drive change. You’ll own the delivery of practical solutions to solve real-world problems for customers, with the knowledge that what you build has an immediate positive impact. For this role we’re specifically looking for someone who has built large scale multi-tenanted search systems.

You’ll face exciting technical challenges as we scale, and be an integral part of the engineering team. High-performing teams here own their services, and you’re trusted to build and run a system that serves millions of users while transforming it into a system that will serve tens of millions of users in the near future. We empower engineers to learn new skills and use technology to solve customer problems, including initiatives in IoT, machine learning, and event-driven architecture.

This role is part of our Best Fit job match program. We have a variety of Software Engineering roles, by applying to this role will be considered for multiple roles across our engineering teams. We want to set you up for success in your role so we assess your capabilities and then match you up to the best team.

Key Responsibilities

• Design, build and operate large-scale search across front end and back end, in a stack of React, TypeScript, Golang, PostgreSQL and OpenSearch running on AWS.

• Own the search relevance and retrieval-quality. Define how relevance is measured, then drive it up through ranking, query pipelines, and tuning.

• Lead search architecture: indexing strategy, hybrid retrieval (combining lexical text search with semantic/vector search), embeddings, and ranking, including the trade-offs each involves.

• Build AI-native applications, connecting retrieval to LLM-powered experiences (e.g. RAG), and stay at the bleeding edge of agentic coding tools.

• Provide technical leadership guiding search architecture, execution, and cross-functional collaboration to deliver impactful outcomes.

• Own search feature delivery end-to-end: breaking down requirements with stakeholders, partnering with Product and Design, supporting other engineers, and ensuring successful delivery.

• Articulate effort-vs-impact trade-offs, including build-vs-buy decisions.

• Keep search operable at scale, performance, observability, and cost as data volume grows.

• Drive high-performance team outcomes by setting rigorous engineering standards, mentoring peers, and improving team practices for quality, velocity, and collaboration.

• Demonstrate Mitti’s values (Think Customer; Open, Honest, Always; Better as a Team; Be Bold, Bring Action).

About you

• Deep search / information-retrieval expertise: lexical text search (inverted indexes, BM25-style ranking), semantic and vector search (embeddings, approximate nearest-neighbour), hybrid retrieval, and relevance tuning.

• Hands-on with RAG: chunking, retrieval pipelines, grounding model outputs, and evaluating retrieval quality.

• Proven track record building search capability into new or existing applications that retrieve information at scale in a multi-tenanted architecture.

• Strong OpenSearch / Elasticsearch operating experience at scale, including how segment merging works and the operational challenges that architecture presents.

• A systems thinker who decomposes large problems into small ones and teaches less experienced engineers to do the same.

• Works autonomously and is comfortable making the call without waiting on sign-off; co-owns technical and product direction rather than building to someone else’s spec.

• Influences where the product goes, not just how it gets built.

• Thrives in a small team at a fast pace, comfortable with little formal process and structure.

• If you have used turbopuffer in production before, let us know!

More than a job

• Equity with high growth potential, and a competitive salary

• Flexible working arrangements

• Access to professional and personal training and development opportunities

• Hackathons, Workshops, Lunch & Learns

• In-house Culinary Crew serving up daily breakfast, lunch and snacks

• Barista coffee machine, craft beer on tap, boutique wines and a range of non-alcoholic beverages

• Wellbeing initiatives such as EAP services and generous parental leave policy

• Quarterly celebrations and team events

• On-site gym, table tennis, board games, books library, and pet-friendly offices

We’re committed to building inclusive teams and cultivating a sense of belonging so our people can bring their whole authentic selves to work each day. We seek to make reasonable adjustments throughout our recruitment process to create an even playing field for all candidates. Thanks to the tireless efforts of the entire Mitti team we’ve built an incredible culture which has seen us recognised as a Best Place to Work in Australia , the US and the UK .

You can find out more about life at Mitti via Youtube , Twitter , Instagram and LinkedIn.

To all recruitment agencies, we do not accept resumes or partnership opportunities. Please do not forward resumes to Mitti or any of our employees. We are not responsible for any fees associated with unsolicited resumes.