Development

Business software built to survive its second year

Operational systems where the difficult parts are the ones nobody demos: tenant isolation, approval chains that hold under delegation, stock that cannot be double-promised, and a ledger that still reconciles after a partial payment.

Case studies: 9 platforms
Domains: Sales, HR, finance, operations
Stack: Next.js, TypeScript, PostgreSQL
Technical preview: Behind a shared keyword

The platforms

9 case studies · project type stated on every card

eluno / customer recordquotation v2

customer · Sundaram Traders6 events

Enquiry04 Mar· Priyaphone · 2 items discussed
Quotation v105 Mar· Priya₹48,200 · sent on WhatsApp
Quotation v207 Mar· Ownerprice agreed verbally · 2 lines changed
Job confirmed08 Mar· Ownerv2 copied onto job · frozen
Delivery 1 of 214 Mar· Ramesh6 of 10 units · partial
Payment15 Mar· Priya₹20,000 part payment · allocated

nothing is edited in place

A revision adds a row. The owner can point at the moment a price changed and who changed it, which is the only thing that settles an argument about what was agreed.

quotation Q-1184 · v2 against v12 lines changed

line	v1	v2 · agreed
Ledger binding — A4	10 × ₹2,900	10 × ₹2,900
Ledger binding — A3	4 × ₹3,400	4 × ₹3,050changed
Lamination	10 × ₹520	10 × ₹520
Delivery	₹1,200	includedchanged

discount, made visible

₹2,600 was given away across two lines. Before this existed, the difference showed up only as a total that did not match the quotation.

Ageing is computed from the charge dates every time this is opened. There is no stored balance on the customer, because a stored balance is a second version of the truth and it goes wrong without telling anyone.

Reconstruction

01MSME operationsSoftware

Eluno

Business software for small enterprises

Business software for a small enterprise that had outgrown notebooks and WhatsApp but was never going to buy an ERP.

MSMEBusiness softwareClient project

Private client project

platform / enquiry triage2 unassigned

enquiries · oldest first2 unassigned

from	route	waiting
Logistics operator, Puneunassigned	form	2h
Dental practice, Chennaiunassigned	email	6h
Equipment hire, KochiclaimedSuraj	referral	1d
Textile exporter, SuratquotedSuraj	form	3d

ordered by age, not by size

A small enquiry left for three days is the one that costs a referral.

E-2291 · summary beside the originalmodel output

as received · 340 words

“…we have been managing everything on sheets and a group, but customers keep calling to ask where their order is and we cannot always answer quickly…”

stated

Wants order tracking visible to their own customers
Currently on spreadsheets plus a WhatsApp group
Around 40 orders a week

not specified · ask these

Budget
Timeline
Who else needs access
Whether invoicing is in scope

inferred · not said by the sender

Likely wants a customer-facing portal, not only internal screens

acknowledgement

sent at +0.4s · before the model ran

if summarisation fails

record unaffected · original readable

prompt version stored

enquiry-summary/v4

Reconstruction

02Agency operationsSoftware

NexviaTech Platform

Agency platform

The platform a technology services business runs on: enquiries, proposals, project tracking and the public site, in one codebase.

Agency platformProposalsProject tracking

NexviaTech

automly / localisation matrixen · ar

direction rules · per element4 flip · 3 pinned

element	ltr	rtl
Section paddingresolves by direction	inline-start	inline-start
Next-step arrowresolves by direction	→	←
Nav orderresolves by direction	left to right	right to left
Wordmarkpinned	as drawn	as drawn
Phone numberpinned	+966 …	+966 …
Product screenshotpinned	as captured	as captured

never mirrored

A flipped screenshot of the product is a false picture of the product. A flipped wordmark is somebody else’s logo.

routing · one page, two addressesbuild output

path	dir	resolution
/en/pricing	ltrlang=en	canonical · alternate → /ar/pricing
/ar/pricing	rtllang=ar	canonical · alternate → /en/pricing
/pricing	—	308 → /en/pricing · resolved once

type scale, defined per language

17px / 1.55

Reads at the intended weight.

18px / 1.75

Same nominal size looked lighter and cramped.

missing translation key

build fails · no silent fallback

direction decided

server-side · no flip on first paint

content fetched at runtime

none · static per language

Architecture

03Product presentationSoftware

Automly

Product website and workflow presentation

A multi-language product front end for a business tool, where the routing and layout had to work identically in two reading directions.

Product front endLocalisationFrontend architecture

Abdulrahman Qumsani · Saudi Arabia

crm / pipelinetenant scoped

tenant: fairoak-group · pipelinerole: sales manager

Ashvale Logistics

Marlow Interiors

+4 more

Trellis Foods

Cobalt Dental

+2 more

Northline Components

+1 more

Verity Studio

+2 more

scoped data access

Application code never holds a database connection. It receives a client already bound to a tenant and a permission predicate, so tenant scope is not something a query can forget.

out-of-scope reads

Return not-found rather than forbidden. A distinct error message confirms the record exists somewhere, which is itself a leak.

custom fields · 14 defined for this tenant · validators compiled per stage

Reconstruction

04Customer relationshipsSoftware

Multi-Tenant CRM — Reference Build

A CRM each business configures to its own pipeline, built so one tenant’s data cannot be reached from another’s session.

SaaSMulti-tenantCRM

Self-directed build — no clientpreview

ats / panel scheduling2 viable slots

req ENG-114 · panel scheduling2 viable slots · 19 Mar

Calendar	09:00	09:30	10:00	10:30	11:00	11:30	12:00	12:30
Candidate IST · self-selected
P. Raman Panel · engineering
A. Khanna Panel · hiring manager
Room 2 Resource
Intersection

funnel · this requisition

Applied148
Screened41
Interviewing12
Offer2

blind scorecards

Until an interviewer submits, other scorecards for that stage are withheld by the server — not hidden by the interface. Enforcing it client-side means the data was already sent.

timezone handling

Availability is merged, inverted and intersected as UTC intervals. Local time exists only at the point of display, which removes an entire class of off-by-one-hour bugs.

Reconstruction

05HiringSoftware

Recruitment & Applicant Tracking — Reference Build

Runs hiring on structured scorecards instead of opinions, finds interview slots across a panel’s real calendars, and stops candidates going silent.

HR techSchedulingWorkflow

Self-directed build — no clientpreview

procurement / rfq comparison3 quotes

rfq 2026-118 · comparison on landed cost3 responses

Supplier	Unit	Freight	Non-recov. tax	Terms	Landed
Northline Componentslowest landed	11.40	2,400	0	Net 45	48,120
Harrow Supply Co	10.95	5,600	1,180	Net 15	49,540
Delcon Traders	11.10	3,100	0	Advance	49,180

lowest unit price is not lowest cost

Harrow quotes 10.95 per unit — the cheapest line on the page — and lands 1,420 higher once freight under their incoterm and non-recoverable tax are included.

budget · maintenance / Q178% committed

approved: 620,000
committed: 483,700
available: 136,300

Commitment is checked and written under a row lock, so two buyers approving at the same moment cannot both spend the last of a budget line.

award and PO

Award reason recorded. Choosing anything other than lowest landed cost requires a written justification.
Commitment released on receipt. The reservation is reversed with a negative entry rather than an edit, so the history stays intact.
Chain frozen at submission. Later changes to the approval policy do not silently rewrite an in-flight requisition.

Reconstruction

06PurchasingSoftware

Procurement & Purchase Order — Reference Build

Checks budget before a commitment is made, compares supplier quotes on true landed cost, and makes the purchase order the instrument that authorises an order, not paperwork that follows one.

FinanceApprovalsOperations

Self-directed build — no clientpreview

warehouse / stock positionBLR-01

warehouse BLR-01 · stock positionderived from movement ledger

Item	On hand	Reserved	Inbound	Available
Steel bracket, M8 BRK-M8-SS	1,840	620	400	1,220
Nylon washer, 6mm WSH-NY-06	240	240	1,200	0 · fully reserved
Epoxy adhesive 500ml ADH-EP-500	96	12	0	84

allocation · FEFO · 60 unitsADH-EP-500

Batch	Expires	Available	Picked
B-2409	2026-09-30	24	24
B-2502	2027-02-28	48	36
B-2508	2027-08-31	24	0

dated stock first, then oldest received · overrides require a recorded reason

append-only movement ledger

Quantity is never updated in place. Receipts, picks, adjustments and transfers are movements, and the position is their sum — so a discrepancy can always be traced to the movement that caused it.

cycle count variance

A count writes an adjustment movement with a reason code. The count is evidence, not an overwrite of the history.

reservation locking

Reservations are taken under a per-item lock on a rollup row, so two orders cannot reserve the same last unit.

Reconstruction

07Stock controlSoftware

Inventory & Warehouse — Reference Build

Treats stock as a ledger of movements, not an editable number, so what the system says is on the shelf can be traced to why.

OperationsInventoryLedger

Self-directed build — no clientpreview

delivery / allocation grid1 conflict

allocation grid · weeks 11–161 conflict

Person	W11	W12	W13	W14	W15	W16
P. Raman Engineer	32h	40h	46h	40h	24h	leave
A. Khanna Engineer	16h	24h	40h	40h	40h	32h
S. Mehra Designer	8h	8h	20h	leave	16h	24h

over-allocated · P. Raman · W13

46 hours committed against 40 available. Fairoak migration holds 30 and Northline integration holds 16 — the conflict names both projects, so the decision is which to move rather than whether a problem exists.

rate frozen at approval

Cost is written onto the time entry when it is approved. A later rate change cannot retroactively rewrite last quarter’s project margin.

effective-dated rates

Cost and bill rates are dated series. Inserting a new rate closes the previous open-ended row rather than overwriting it.

period lock

W09 and earlier are locked. Back-dated entries are rejected on the write path, not hidden in the interface.

Reconstruction

08Professional servicesSoftware

Professional Services Resource Planning — Reference Build

Tells a services business which projects are actually profitable, using effective-dated cost rates and allocation that accounts for who is already booked.

ServicesPlanningProfitability

Self-directed build — no clientpreview

leasing / ledgerlease L-2043

lease L-2043 · unit 4B · ledgerbalance 28,100

Date	Entry	Charge	Payment	Balance
01 Jan	Rent · Jan 2026	28,000		28,000
05 Jan	Payment · UPI ref 4471		28,000	0
01 Feb	Rent · Feb 2026	28,000		28,000
09 Feb	Late fee · after 7d grace	700		28,700
01 Mar	Rent · Mar 2026 (escalated 5%)	29,400		58,100
12 Mar	Payment · bank transfer		30,000	28,100

deposit held 56,000 · tracked separatelyentries are append-only · a waiver is a reversing entry

payment 30,000 · allocation previewpolicy order

Late fee · 09 Febcleared
due 700applied 700
Rent · Feb 2026cleared
due 28,000applied 28,000
Rent · Mar 2026part
due 29,400applied 1,300

waterfall

Fees, then oldest outstanding charges, then current. Applied identically every time, so any balance on the ledger can be reconstructed from the payments that produced it.

schedule generation

March shows the 5% anniversary escalation with its clause and base recorded. First and last months are pro-rated on day count in integer minor units, and the term is asserted to reconcile exactly.

Reconstruction

09Real estate operationsSoftware

Property & Lease Management — Reference Build

Generates rent schedules from lease terms, allocates part payments the same way every time, and keeps a ledger per lease that both sides can read.

Real estateBillingLedger

Self-directed build — no clientpreview

Foundations

Four decisions made before the first screen

They are unglamorous, and they are the reason a system can absorb a new requirement in month eight without a rewrite.

The schema is the product

Entities, states and the transitions between them are designed before any screen exists. Most business software that becomes unmaintainable got the data model wrong in week one and spent the next year working around it.

Rules live on the server

Permissions, approval thresholds and period locks are enforced on the write path. Anything enforced only in the interface is a suggestion.

History is append-only

Ledgers, movements and audit entries are added, never edited. A balance you cannot reconstruct is a balance you cannot defend in a dispute.

Money is integers

Amounts are held in minor units. Proration, percentage escalations and tax all produce repeating decimals, and floating-point drift in a finance system becomes a customer-facing error.

Stack

What these platforms are built with

Deliberately boring choices. A business system is a long-lived asset, and novelty is a cost its owner pays for years.

Full capability list

Product and application engineering: Next.js App Router
React with Server Components
TypeScript (strict)
Tailwind CSS design systems
Data tables, filtering and saved views
Accessible components and keyboard flows
Backend and APIs: Django and Django REST Framework
FastAPI
Node.js
REST API design and versioning
Authentication, sessions and JWT
Role and permission models
Data modelling and storage: PostgreSQL schema design
Multi-tenant isolation patterns
Append-only ledgers and derived balances
State machines and status invariants
Audit trails and effective-dated records
Query performance and indexing
Delivery and infrastructure: Docker and container builds
Google Cloud Run, Cloud Storage
Vercel deployment and edge caching
CI pipelines (GitHub Actions, Jenkins)
Environment and secret management
Logging, tracing and error reporting

Software engagement

Replacing a spreadsheet with something that scales?

Describe the process, who touches it and where it currently breaks. You will get a data model sketch, a technical approach and a timeline before any commitment.

Start a project View work

Email: surajk86808@gmail.com
Based in: Bengaluru, India
Working hours: IST (UTC+5:30)
Availability: Taking new engagements