Senior Back End Engineer Java/OLAP

United States Digital Space LLC; Toronto; On-site; CAD 130,000 - 160,000; Full time

Benefits offered by this job

Health benefits

Retirement savings plan

Generous time off

Job summary

One™ is seeking a Senior Back-End Engineer specializing in Java and OLAP to own the Java side of our OLAP cube engine. You will design, optimize, and scale cube capabilities, working closely with the .NET Cube module team to ensure correctness and performance as models grow.

You will drive performance, implement robust tests, and help evolve contracts between services across the stack. This role is based in Canada’s GTA region and offers a chance to impact finance planning platforms at scale.

Qualifications

• 5+ years of professional Java development experience with JVM-based OLAP or multi-dimensional data engines.
• Strong understanding of multi-dimensional data modeling: dimensions, hierarchies, measures, and aggregation semantics.
• Experience profiling and optimizing JVM applications for latency/throughput in production.
• Ability to design and evolve a service contract consumed by a separate .NET service.
• Experience with unit and integration testing in an Agile, TDD mindset.

Responsibilities

• Design, build, and optimize OLAP cube capabilities in Java and Atoti, including dimension/hierarchy modeling, calculated measures, and aggregation performance.
• Own the performance-critical path of cube operations with low latency and correctness.
• Collaborate with the .NET Cube module team on data merging, dimension/conversion strategies, and cache management.
• Investigate and resolve OLAP defects including hierarchy resolution and edge-case handling.
• Profile and tune cube queries and calculations as models scale, ensuring production reliability.
• Define and evolve the contract between the cube engine and .NET/Postgres consumers across releases.
• Write thorough unit and integration tests for cube logic and financial correctness.

Skills

Java development

JVM performance tuning

Unit & integration testing

Git & CI/CD

English communication

Education

Post-secondary degree in computer science or related

Tools

Atoti

ActivePivot

PostgreSQL

.NET familiarity

Job description

See what you can do with the company

At the company, we’re building the platform that helps finance teams stop managing spreadsheets and start driving strategy. the company One™ brings planning, reporting, consolidation, and automation together in a single place, and we are expanding its AI capabilities faster than ever. If you want to work on a product that genuinely changes how finance teams operate, and do it alongside people who care about getting it right, this is where you want to be.

We’re headquartered in the Greater Toronto Area, with teams and offices across North America, Europe, and Australia. Trusted by more than 3,000 finance teams across 100+ countries, the company One™ is built for organisations that want to plan smarter and move faster.

At the company, the OLAP cube engine sitting at the heart of FP\&A Plus is what makes every budget, report, and multi-dimensional calculation possible for more than 3,000 finance teams worldwide. As a Senior Back-End Engineer specializing in Java and OLAP, you will own the Java side of that engine — designing, optimizing, and scaling the cube capabilities that our customers depend on every day. You will work in close partnership with the .NET Cube module team to keep the engine and its consumers in lockstep, ensuring correctness and performance hold up as customer models grow in complexity and scale.

Requirements

What You Will Do

• Design, build, and optimize OLAP cube capabilities in Java and Atoti, including dimension and hierarchy modeling (alternate and parent-child hierarchies), calculated measures, and aggregation performance across large, real-world customer data volumes.
• Own the performance-critical path of cube operations — member selection, calculation over large hierarchies, and data write/merge paths — where both correctness and low latency are non-negotiable.
• Partner closely with the .NET Cube module team on dimension and fact conversion, cube data merging, and cache strategy, keeping the Java engine and its .NET consumer aligned as cube contracts evolve.
• Investigate and resolve OLAP-specific defects, including hierarchy resolution edge cases, aggregation correctness issues (such as zero-denominator and boundary-value handling), and member-property semantics that must match customer expectations exactly.
• Profile and tune cube query and calculation performance as models scale in dimension count, member count, and hierarchy depth, continuously pushing the performance envelope under production conditions.
• Define and evolve the contract between the cube engine and its .NET/Postgres-backed consumers — including response shapes, versioning, and backward compatibility — ensuring existing consumers are never broken across releases.
• Write thorough unit and integration tests for cube logic, upholding the financial correctness that customers rely on at every layer of the engine.

What You Will Bring

We hire for potential as much as experience. If this role excites you but you don’t check every box, we still want to hear from you. At the company, people who ask good questions, adapt quickly, and bring a fresh perspective often make the biggest impact.

Required Qualifications

• 5+ years of professional Java development experience, including production experience with a JVM-based OLAP or multi-dimensional data engine such as Atoti/ActivePivot or a comparable technology.
• Strong understanding of multi-dimensional data modeling: dimensions, hierarchies (including parent-child and alternate hierarchies), measures, and aggregation semantics.
• Demonstrated experience profiling and optimizing JVM applications for latency and throughput under real production load.
• Proven ability to design and evolve a service contract consumed by a separate application — in this case a .NET service — without breaking existing consumers.
• Practiced with unit and integration testing, with an agile and test-driven development mindset.
• Fluency with Git source control and CI/CD workflows.
• Post-secondary degree in computer science, software engineering, or a related discipline, or equivalent working experience.
• Strong written and verbal English communication skills and the ability to collaborate effectively across polyglot engineering teams.
• Legally entitled to work in Canada.
• Must be legally entitled to work in the country where this role is located
• Comfortable using AI tools responsibly to support tasks such as research, drafting, and data review
• Able to learn new tools and adapt as technology and workflows evolve.
• Curious, open to new approaches, and motivated to continuously improve.
• Collaborative mindset when working across teams and with AI supported tooling.

Preferred Qualifications

• Direct, hands‑on experience with Atoti/ActivePivot specifically, beyond general JVM-based OLAP familiarity.
• Exposure to the .NET ecosystem sufficient to collaborate effectively across a polyglot service boundary.
• Experience with PostgreSQL as the underlying data store for an OLAP layer, ideally on a managed or serverless offering such as AWS Aurora Serverless.
• Academic or practical knowledge of corporate financial concepts — planning, budgeting, forecasting, or consolidation — to better understand the calculations this engine is built to serve.
• Experience with cloud-native deployment of JVM services on AWS, including containerization.

Benefits

What Success Looks Like

• 30 days: You know our platform, our customers, and how your team operates. You’ve completed onboarding and is contributing to live work.
• 90 days: You’re working independently, owning deliverables end to end, and building relationships across functions and regions.
• 6 months: Your fingerprints are on something real. You’ve improved a process, shipped something meaningful, or earned a seat at the table on a decision that matters.

Why Join the company?

the company is headquartered in the GTA, so joining our team puts you close to where decisions are made, strategy is set, and careers are built. You’ll collaborate across North America, Europe, and Australia, developing breadth you simply can’t get at a single market company. Our people move across functions, work directly with customers in different industries, and take on meaningful challenges early. We’re a company that competes on talent. That means we invest in the people who show up curious, move fast, and want to leave things better than they found them. Our values are Pursue Excellence, Build with Purpose, Create Wins for All, and Drive Continuous Innovation, and they guide how we actually make decisions.

Compensation

The total target compensation for this role is $130,000CAD to $160,000CAD, in accordance with applicable pay transparency laws. Actual compensation will be determined based on factors such as skills, experience, location, and internal equity.

What’s Included for You?

• Comprehensive health, dental, vision, and mental-health coverage
• Retirement savings with employer contributions
• Parental leave top-up
• Annual wellness allowance
• Generous paid time off including vacation and sick time
• Education assistance and tuition reimbursement
• Social events, team activities, and opportunities to build community
• Opportunities to participate in Environmental, Social, and Governance (ESG) initiatives
• Quarterly Town Halls and Kickoffs that bring teams together to celebrate wins, share updates, and look ahead at what’s next

Accessibility & AI Transparency

the company promotes an accessible hiring process. If you need accommodation at any stage, we’ll work with you. Some interviews may be recorded so our hiring team can review and assess responses fairly and consistently. As part of our commitment to Responsible AI, we use a small number of AI-supported tools to help with tasks like resume review, shortlisting, or creating interview summaries. AI is never used as the sole basis for hiring decisions, and your personal data is never used to train AI models. If you'd prefer not to take part in any AI-assisted step, just let us know and we’ll be happy to accommodate.