Engineer
Siiibo証券 (Siiibo Securities) is a Japanese registered securities company (Type I Financial Instruments Business Operator) that enables individual and corporate investors to invest in privately placed corporate bonds issued by mid-to-late stage startups and newly listed companies. It offers yen-denominated fixed-rate interest income opportunities, secondary market trading, and a diversified, low-fee investment platform.
Funding
Investors
Projects
About Siiibo証券
Siiibo証券 operates a securities platform focused on startup investment through corporate bonds (社債), particularly small-lot private placement bonds (少人数私募社債) limited to a maximum of 49 investors per issue. The company primarily serves mid-to-late stage startups and newly listed companies seeking financing beyond their early growth phase, offering bond terms with yields ranging roughly 2-8% and maturities of 1-4 years, with typical investment amounts of 50-3,000,000 yen. Investors can browse company IR information, submit investment preferences, purchase bonds with no purchase fees, monitor issuers during the holding period, and receive interest and principal repayments at maturity. Unlike social lending, these bonds are classified as first-class securities, allowing trading on a secondary market for liquidity before maturity. As a registered Type I Financial Instruments Business Operator, the company maintains segregated asset management, is covered by the Investor Protection Fund (up to 10 million yen), and has implemented security measures including passkey authentication for login.
Skills
About the Role
You'll work on Siiibo, a web platform that connects lenders and borrowers through a private bond marketplace, handling everything from investor selection to private bond issuance. Depending on your area of focus, you may build the client web application, develop server-side logic and APIs, manage infrastructure, support corporate IT, or assist with project management and development processes. You'll collaborate with a small, tight-knit team that values asynchronous text communication and thorough code review on GitHub Pull Requests.
Requirements
- Experience in web application development in a desired area of responsibility
- Experience in multiple business web application development projects
- Self-taught or non-professional web application development experience
- Experience programming in functional languages
- Experience with Elixir, Erlang, Scala, Haskell, OCaml, Elm, or PureScript
- Interest in application development using functional languages
- Comfort thinking in terms of types and interfaces
- Programming experience through research, coursework, or self-study (for students)
- Experience with middleware-based server frameworks such as Ruby on Rails, Express.js, or Phoenix
- Experience with SPA development using VirtualDOM and pure state management such as Elm or React with Redux
- Experience in small-team development
- Experience with code-review-centered team development
- Comfort using git and GitHub for development
- Experience using Docker for development
Responsibilities
- Design and prototype screens and implement SPA-style client applications
- Integrate with server APIs and improve UX
- Design UI for regulatory-compliant customer explanations
- Write unit and E2E tests
- Design DB tables and API schemas
- Implement migrations and business logic constraints
- Implement user notification features
- Implement and test asynchronous processing
- Implement logging and statutory ledger data output
- Perform resource scheduling and build metrics/trace collection systems
- Build uptime monitoring systems
- Maintain log investigation processes and documentation
- Set up incident response processes
- Maintain internal IT infrastructure including networking and device kitting
- Maintain internal tools and bots and automate business workflows
- Provide internal IT helpdesk support education and documentation
- Automate routine development workflow tasks
- Visualize project progress
- Organize and structure Trello and Esa
Benefits
- Full social insurance (health insurance, employees' pension, workers' accident compensation insurance)
- Nearby residence allowance
- Special leave of 5 days granted upon joining in addition to regular paid leave
- Full transportation expense reimbursement
- PC and business equipment provided
- Remote work option for employees upon request
- Fully remote work possible for contractors