Chapter 293: Boundary Conditions

At 7:00 a.m., the alarm hadn’t gone off, but Lin Chen was already awake. His old left ankle injury always flared up before the weather forecast on damp, overcast days, feeling like a rusted steel needle wedged into the bone seam, throbbing dully with each pulse. He sat up, left the lights off, and fumbled for the empty ibuprofen blister pack on the nightstand, popping out two more pills. After swallowing them with cold water, he drew back the curtains. Gray-white daylight filtered in, falling across the open error notebook on his desk. Beside the Gantt chart nodes he’d crossed out in red pen last night, timestamps and risk coefficients were densely annotated. Seven lines remained, like seven trenches waiting to be filled.

He powered on his laptop and logged into the co-managed account backend. Zhao Qiming’s four hundred thousand had arrived, its status reading “Frozen, pending technical milestone unlock.” Lin Chen didn’t touch the funds immediately. He opened his financial spreadsheet and split the budget into three blocks: one hundred twenty thousand for compute scaling, thirty-five thousand for third-party penetration testing, and forty thousand for the labeling team’s labor and compliance documentation. The remaining two hundred thousand went into a buffer pool, locked and untouched. Capital’s money is hot to handle; he needed to leave himself ample room for error. Every expenditure had to correspond to a specific deliverable on the checklist. No compliance, no disbursement. This was the rule he’d negotiated with Zhao Qiming, and the insurance policy he’d written for himself.

At 9:00 a.m. sharp, the online technical meeting began. Su Man’s avatar lit up, her background showing a server room packed with racks. “The data anonymization script v3.1 ran against five thousand samples last night. Coverage hit 99.6 percent. The remaining 0.3 percent is stuck on the radiology department’s historical archive data.” Her voice carried the rasp of an all-nighter. “Those are DICOM files from ten years ago. The field names are all pinyin abbreviations. Regex matching fails outright. The labeling team tried two rounds, but the false positive rate is still too high.”

Lin Chen nodded, his fingers tapping a few lines into the meeting chat: “Don’t force the regex. Write a mapping table. Create a one-to-one correspondence between the radiology department’s common pinyin abbreviations and standard medical terminology. Have the labeling team manually align three hundred samples today and get me the mapping dictionary by 5:00 p.m. Have you contacted the penetration testing firm?”

“Yes. ‘Andun Tech.’ They’re registered with the Health Commission. Their quote is thirty-two thousand, plus a three-thousand rush fee. They require on-site access tomorrow, which means opening external ports on the test environment and providing system access logs from the past three months.”

“We can’t open all the ports,” Lin Chen said evenly. “Only 443 and 8080, with an IP whitelist. Export the logs after anonymization. I’ll sign the contract this afternoon. The initial payment will come from the co-managed account’s testing fund. Su Man, you monitor the pentest progress. I’ll handle getting the mapping table and anonymization logic running smoothly. The assessment team arrives in nine days. We only get one shot.”

The meeting ended. Lin Chen muted his mic and returned to his code editor. The radiology pinyin abbreviations were a tough nut to crack. Was XG a chest X-ray or a blood vessel? Was FY pneumonia or a follow-up visit? Without context, the algorithm was blind. He pulled up the interface documentation for the hospital’s legacy system and discovered that a decade ago, data entry clerks had heavily relied on custom shorthand to save time. This wasn’t a technical problem; it was a historical artifact of human habit.

He created a new Python script. No complex models, just rules. Using pandas, he parsed historical work orders, extracted high-frequency abbreviations, and cross-referenced them with department shift schedules and doctors’ signature habits. Anything uncertain was flagged as [MANUAL_REVIEW]. He wasn’t chasing full automation; he was chasing traceability. Every line of replaced data had to have its original hash value and replacement rationale logged. Compliance audits didn’t demand perfection; they demanded an unbroken chain. On the paper notebook beside him, arrows and decision boxes mapped out data flows. Whenever he hit an uncertain boundary condition, he paused, tracing the logic on paper with his pen tip. It was just like back in the main hall of Qingshi Village, dismantling syntax on that secondhand computer. Slow, but steady.

At 2:00 p.m., the first draft of the mapping dictionary was generated. Out of three hundred samples, two hundred eighty-seven had been manually aligned. The remaining thirteen were genuine rare characters and garbled text. Lin Chen isolated them and drafted an “Abnormal Data Handling Instructions” document. This would accompany the anonymization script as reference material for the assessment team. He printed it out and proofread it word by word. The sound of paper rustling was unusually sharp in the quiet office. The ibuprofen was wearing off, and the stabbing pain in his left foot crept back up. He stood, paced slowly down the narrow aisle twice to loosen his stiff joints, and sat back down at the screen.

At 3:10 p.m., he called Andun Tech’s business line. He confirmed the contract details and sent over the stamped scan. The co-managed account’s approval process took forty minutes before the thirty-five thousand was transferred. Lin Chen stared at the bank statement, his fingertips growing slightly cold. This wasn’t an expense; it was buying an entry ticket. If the penetration test failed, or if the assessment team nitpicked the data traceability, this money would vanish. But he had no choice. Compliance was the bottom line. Crossing it meant death.

At 4:00 p.m., Su Man sent a message: “Test environment ports configured. Andun’s engineers arrive tomorrow at 9:00 a.m. Also, Director Liu from the IT department replied. The ‘Data Flow Ledger’ required by the assessment team can’t be fully exported from the hospital system. It needs manual backfilling.”

Lin Chen stared at the screen. Manual backfilling. That meant tracing six months of data access records, manually entering every API request, every model inference, and every result return into Excel. Thousands of entries. One wrong timestamp, and the ledger wouldn’t reconcile. He rubbed his temples and replied: “Send me the template. Split the labeling team into two groups: one for data cleaning, one for ledger backfilling. I want a first draft tonight.”

The moment the message went out, his phone vibrated again. An alert from the test environment monitoring group: [ERROR] PACS system interface pull failed, HTTP 502.

Lin Chen opened the logs. The radiology department’s legacy PACS system threw an error the moment it tried to pull data in the test environment. He pulled up the packet capture and found a mismatch in the underlying protocol version. The decade-old interface used the outdated SOAP protocol, while the current gateway defaulted to RESTful. A protocol gap had completely choked the channel.

He called Director Liu. The man answered, his tone carrying its usual exhaustion: “Engineer Lin, it’s not that we’re unwilling to cooperate. That PACS system was installed ten years ago. The original vendor’s maintenance contract went bankrupt three years ago. Nobody dares touch the underlying code. If it breaks, the entire hospital’s imaging access goes down. The data you need for the assessment, we really can’t export it.”

“We don’t need to modify the core,” Lin Chen said calmly. “We just need a read-only middleware interface. We’ll write an adapter layer to convert the SOAP protocol to JSON. We won’t touch the core database. I’ll bring an engineer over tomorrow morning for on-site debugging. Two hours, max.”

There was a few seconds of silence on the other end. “Alright. 8:00 a.m. tomorrow, IT server room. But Engineer Lin, let’s be clear upfront: if you crash the legacy system, the liability falls on you.”

“Understood. We’ll only do passive capture. No writes to the database.”

He hung up, closed his laptop, and stood. As his left foot hit the floor, pain shot up his calf. He braced himself against the desk for a few seconds, then walked to the window. Below, the streets were heavy with traffic, traffic lights cycling through their colors. The nine-day countdown had already transformed into concrete, granular, hands-on trenches that had to be filled.

He grabbed his coat and backpack, stuffing the error notebook and the stack of “Abnormal Data Handling Instructions” inside. Before leaving, he wrote tomorrow’s to-do list on the whiteboard: 1. Andun onboarding & coordination 2. Ledger backfill task division 3. Final test of radiology mapping table 4. Visit City First Hospital IT Dept, establish PACS passive interface.

The elevator descended. The metal walls reflected his slightly weary face. His phone buzzed—a WeChat message from Zhao Qiming: “List signed. First tranche released. Lin Chen, don’t trip over compliance. The market waits for no one.”

Lin Chen didn’t reply. He stepped out of the office building, the early autumn wind carrying a chill. He hailed a taxi and gave the address for the City First People’s Hospital. The real battle wasn’t in the code; it was in those old systems worn smooth by time, in those workflows where “good enough” had become the standard. He had to go on-site and fill every crack, inch by inch.

The car merged onto the elevated highway. Lin Chen leaned back against the seat and closed his eyes. There were no grand visions in his mind, only fields waiting to be verified, forms waiting for signatures, boundaries waiting to be crossed. In nine days, the assessment team would arrive with magnifying glasses. And before then, he had to turn every gray area into auditable clarity.

His phone lit up again. A voice note from Su Man popped up, background noise audible: “Lin Chen, there’s a problem in radiology. The old PACS interface protocol is incompatible with the current setup. The test environment throws a 502 error the moment it pulls data. Director Liu says they don’t have permission to modify the core and need the original vendor. But the vendor went bankrupt three years ago.”

Lin Chen opened his eyes. 502 error. Vendor bankrupt. Protocol gap.

He replied: “Send me the error logs and packet capture. I’m bringing my laptop over. We have to open the channel tonight.”

Outside the window, streetlights blurred into a continuous yellow line. Lin Chen gripped his phone, his knuckles turning slightly white. Beyond the boundary conditions, there were more boundaries. He had to dismantle them.